2-(2,2-dihaloethenyl)-5-arylthiophene pesticides

ABSTRACT

Thiophene derivatives of the following formula are effective as acaricides: ##STR1## wherein R A  is selected from -hydrogen, -halogen, -lower alkyl, hydroxy, -lower alkoxy, -lower alkylthio, -lower alkoxyalkoxy, -lower alkoxycarbonyl, -aryloxycarbonyl, -lower alkoxycarbonyloxy, -lower alkylsulfonyl, -lower alkylsulfonyloxy, -arylsulfonyloxy, and -lower alkyl phosphonyloxy; 
     R B  is -hydrogen, or R A  and R B  together are --C 4  H 4  --bridging 2&#39;-3&#39; or 3&#39;-4&#39;; 
     R 3  and R 4  are selected from -hydrogen, -lower alkyl, and -aryl; 
     X is -halogen; and 
     Y is selected from -hydrogen and -halogen.

This application is a continuation of application Ser. No. 869,472 filedJune 2, 1986 now abandoned.

This invention is in the field of heterocyclic organic chemicalcompounds which contain a thiophene nucleus. More particularly, theinvention includes certain thiophene compounds per se, argiculturalcompositions containing the novel compounds, and the method of using abroad class of such compounds to control agricultural pests.

There is increasing scientific evidence that toxic reactions initiatedby light play an important role in natural control of insectpopulations. In the last few years the concept of using photoactiveagents as insecticides has been advanced. Such photosensitizerstypically displayed insecticidal activity by catalyzing the electronictriplet to singlet conversion of molecular oxygen. The excited singletoxygen behaves as a superoxidizing agent, destroying the insect tissueswhich it contacts, hence killing the insect.

According to the present invention,2-(2,2-dihaloethenyl)-5-arylthiophene compounds of the followingstructural formula are photodynamic insecticides and acaricides:##STR2## wherein

R_(A) is selected from -hydrogen, -halogen, -lower alkyl, -hydroxy,-lower alkoxy, -lower alkylthio, -lower alkoxyalkoxy, -loweralkoxycarbonyl, -aryloxycarbonyl, -lower alkoxycarbonyloxy, -loweralkylsulfonyl, -lower alkylsulfonyloxy, -arylsulfonyloxy, and -loweralkyl phosphonyloxy;

R_(B) is -hydrogen, or R_(A) and R_(B) together are --C₄ H₄ -- bridging2'-3' or 3'-4';

R₃ and R₄ are selected from -hydrogen, -lower alkyl, and -aryl;

X is -halogen; and

Y is selected from -hydrogen and -halogen.

In the aforesaid description and wherever the terms appear hereinafter,"halo" and "halogen" mean fluorine, chlorine, or bromine. The term"lower" modifying "alkyl," "alkoxy," and the like, implies a straight orbranched hydrocarbon chain of 1-6, preferably 1-4, carbon atoms. Theterm "acyl" includes phenyl, as well as phenyl substituted with commonsubstituents, such as alkyl and halogen.

Among the aforesaid compounds, it is preferred that R_(A) is -hydrogen,-lower alkoxycarbonyl or -lower alkylsulfonyloxy; R_(B) is -hydrogen;and R₃ and R₄ are independently -hydrogen or -lower alkyl. Specificpreferred compounds include2-(2,2-dibromoethenyl)-4-methyl-5-phenylthiophene,2-(2,2-dibromoethenyl)-3,4-dimethyl-5-phenylthiophene,2-(2,2-dichloroethenyl)-5-(naphth-1-yl)thiophene,2-(2,2-dibromoethenyl)-5-phenylthiophene,2-(2,2-dibromoethenyl)-5-(4-fluorophenyl)thiophene,2-(2,2-dibromoethenyl)-5-(4-acetyloxyphenyl)thiophene, and2-(2,2-dibromoethenyl)-5-(4-methylsulfonyloxyphenyl)thiophene.

The 2-(2,2-dihaloethenyl)-5-arylthiophene compounds of this inventionare prepared by general techniques which form part of the prior art.These techniques are illustrated by the following specific examples:

EXAMPLE 6 2-(2,2-Dibromoethenyl)-4-methyl-5-phenylthiophene

Under a dry nitrogen atmosphere, N-bromosuccinimide (54.4 g, 0.31 mole)was added to a stirred solution of 3-methylthiophene (30.0 g, 0.31 mole)and carbon tetrachloride (80 mL). The reaction flask was covered withfoil to exclude light. The reaction mixture was heated at reflux forfour hours, then was cooled to room temperature and stirred forapproximately 18 hours. The reaction mixture was filtered and thefiltrate evaporated under reduced pressure leaving an oil. Purificationof this oil by fractional distillation under reduced pressure yielded38.2 g of 2-bromo-3-methylthiophene (bp 84°-85° C./36 mmHg).

A stirred mixture of 2-bromo-3-methylthiophene (15.0 g, 0.085 mole) andbis(1,3-diphenylphosphino)propane nickel(II) chloride (0.5 g, 0.009mole) in diethyl ether (75 mL) was cooled to 0° C. Phenyl magnesiumbromide (29.6 mL of a 3M solution in diethyl ether) was added slowly,causing the reaction mixture to reflux. After complete addition, refluxwas continued for 15 minutes. The mixture was cooled, and approximately100 mL of an aqueous 10% hydrochloric acid solution was added. Theresultant mixture was extracted with diethyl ether, and the extract waswashed with an aqueous saturated sodium bicarbonate solution. The washedextract was dried over anhydrous magnesium sulfate and filtered. Thefiltrate was evaporated under reduced pressure yielding 17.3 g of3-methyl-2-phenylthiophene as a colorless oil.

To a cold (0° C.), stirred solution of 3-methyl-2-phenylthiophene (6.0g, 0.034 mole) in dry tetrahydrofuran (80 mL) was added n-butyllithium(16.5 mL of a 2.3M solution in hexanes). After stirring at 0° C. for twohours, the mixture was cooled to -78° C. and N,N-dimethylformamide (10.5mL, 0.14 mole) was added. The mixture was allowed to warm slowly to roomtemperature. Dilute hydrochloric acid was added slowly until the mixturewas acidic. The acidic mixture was extracted with diethyl ether, and theextract was washed with an aqueous saturated sodium bicarbonatesolution. The washed extract was dried over anhydrous magnesium sulfateand filtered. The filtrate was evaporated under reduced pressure,leaving an oil. This oil solidified upon standing in a refrigerator.Purification by recrystallization from diisopropyl ether yielded 5.0 gof 4-methyl-5-phenylthienyl-2-carboxaldehyde (mp 54°-55° C.).

A stirred mixture of 4-methyl-5-phenylthienyl-2-carboxaldehyde (2.0 g,0.01 mole) and triphenylphosphine (5.2 g, 0.02 mole) in 50 mL ofmethylene chloride was cooled in an ice bath. Carbon tetrabromide (3.2g, 0.01 mole) was added to the reaction mixture. After complete additionthe ice bath was removed, and the reaction mixture was allowed to warmto room temperature and was stirred for 2.5 hours. The reaction mixturewas diluted with 200 mL of petroleum ether and stirred vigorously. Themixture was filtered, and the filtrate was evaporated under reducedpressure, leaving an oil. This oil was purified by column chromatographyon silica gel, eluting with petroleum ether, to yield 2.5 g of2-(2,2-dibromoethenyl)-4-methyl-5-phenylthiophene as an oil.

Analysis:

Calc'd for C₁₃ H₁₀ Br₂ S: C 43.60; H 2.81; Found: C 43.30; H 2.63.

EXAMPLE 10 2-(2,2-Dichloroethenyl)-3,5-diphenylthiophene

A stirred mixture of 2,4-diphenylthiophene (10.0 g, 0.042 mole),prepared by the method of Campaigne, J. Am. Chem. Soc., 66, 684 (1944),in dry tetrahydrofuran (90 mL) was cooled to -20° C. A solution ofn-butyllithium (18.8 mL of a 2.7M solution in hexanes) was addeddropwise to the reaction mixture during a five minute period. Aftercomplete addition, the mixture was stirred at -30° C. for two hours,then was cooled to -78° C. N,N-Dimethylformamide (7.2 mL) was added, andthe reaction mixture was allowed to slowly warm to room temperature. Thereaction mixture was poured into 90 mL of an aqueous 10% hydrochloricacid solution, and the resultant mixture was extracted with methylenechloride. The extract was washed with an aqueous solution saturated withsodium chloride. The washed extract was dried over anhydrous magnesiumsulfate and filtered. The filtrate was evaporated under reducedpressure, leaving a solid. Recrystallization of this solid from diethylether yielded 7.6 g of 3,5-diphenylthienyl-2-carboxaldehyde (mp 88°-90°C.).

To a stirred mixture of 3,5-diphenylthienyl-2-carboxaldehyde (3.0 g,0.011 mole), triphenylphosphine (5.9 g, 0.022 mole), and zinc dust (1.5g, 0.023 mole) in methylene chloride (90 mL) was addedbromotrichloromethane (5.4 g, 0.027 mole). After addition, the mixturewas stirred at room temperature for three hous. The reaction mixture wasdiluted with petroleum ether (300 mL), and the resultant mixture wascooled in a freezer for approximately 18 hours, causing an oily residueof the mixture was decanted from the residue. This residue was dissolvedin petroleum ether (400 mL), diethyl ether (100 mL), and methyl iodide(10 mL) and stirred at room temperature for approximately 18 hours. Asmall amount of triphenylphosphine iodide formed and was removed byfiltration. The filtrate was evaporated under reduced pressure, leavinga yellow solid. Purification of this solid by column chromatography onsilica gel, eluting with n-hexane:ethyl acetate (80:20), yielded 2.3 gof 2-(2,2-dichloroethenyl)-3,5-diphenylthiophene as a solid (mp111°-113° C.)

Analysis: Calc'd for C₁₈ H₁₂ Cl₂ S: C 65.26; H 3.65; Found: C 66.68; H4.20.

EXAMPLE 27 2-(2,2-Dibromoethenyl)-5-(4-hydroxyphenyl)thiophene

A mixture of 2-(2,2-dibromoethenyl)-5-(4-methoxymethoxyphenyl)thiophene(8.8 g, 0.02 mole), prepared by the method of Example 6, ethanol (10mL), and two drops of concentrated hydrochloric acid in tetrahydrofuran(50 mL) was stirred at room temperature for approximately 18 hours.Gaseous hydrogen chloride was bubbled into the mixture for severalseconds, after which 10 mL of methanol was added. The resultant mixturewas stirred at room temperature for two hours. This mixture was pouredinto an aqueous saturated ammonium chloride solution and extracted withdiethyl ether. The ether extract was washed with an aqueous saturatedammonium chloride solution. The washed extract was dried over anhydrousmagnesium sulfate and filtered. The filtrate was evaporated underreduced pressure, leaving a solid residue. This residue was dissolved indiethyl ether, and approximately 50 g of silica gel was added to thesolution. The mixture was stirred briefly and filtered. The filtrate wasevaporated under reduced pressure, yielding 7.8 g of2-(2,2-dibromoethenyl)-5-(4-hydroxyphenyl)thiophene as a solid (mp99°-101° C.).

Analysis: Calc'd for C₁₂ H₈ Br₂ OS: C 40.03; H 2.24; Found: C 42.96; H2.52.

EXAMPLE 34 2-(2,2-Dibromoethenyl)-5-(4-acetyloxyphenylene)thiophene

To a stirred mixture of2-(2,2-dibromoethenyl)-5-(4-hydroxyphenyl)thiophene (1.0 g, 0.003 mole)and triethylamine (1.2 g, 0.08 mole) in tetrahydrofuran (20 mL) wasadded acetyl chloride (0.44 g, 0.0056 mole). The reaction mixture wasstirred at room temperature for approximately 18 hours. The mixture wasdiluted with diethyl ether and washed in succession with an aqueous 5%sodium hydroxide solution, water, and an aqueous saturated sodiumchloride solution. The washed mixture was dried over anhydrous magnesiumsulfate and filtered. The filtrate was evaporated under reducedpressure, yielding 0.5 g of2-(2,2-dibromoethenyl)-5-(4-acetyloxyphenyl)thiophene as a solid (mp115°-115.5° C.).

Analysis: Calc'd for C₁₄ H₁₀ Br₂ O₂ S: C 41.82; H 2.51; Found: C 41.95;H 2.42.

EXAMPLE 41 2-(2,2-Dichloroethenyl)-5-(4-methylthiophenyl)thiophene

A solution of N,N-dimethylformamide (40 mL) and phosphorus oxychloride(8.8 mL) was stirred at 0° C. for ten minutes. A solution of2-(4-methylthiophenyl)thiophene (1.5 g, 0.073 mole), prepared by themethod of Example 6 from 2-bromothiophene and 4-methylthiophenylmagnesium bromide, dissolved in N,N-dimethylformamide (150 mL) wasadded. After complete addition, the mixture was stirred and heated on asteam bath for 4.5 hours. The reaction mixture was poured into a coldaqueous 15% sodium hydroxide solution. The resultant mixture wasextracted, first with a 50:50 solution of diethyl ether and ethylacetate, followed by ethyl acetate. The extracts were combined and driedover anhydrous magnesium sulfate. The dried extract was filtered, andthe filtrate was evaporated under reduced pressure, leaving an oil whichsolidified upon standing. Purification of this solid by columnchromatography on silica gel, eluting with n-hexane:ethyl acetate(80:20; 50:50), yielded 12.2 g of5-(4-methylthiophenyl)thienyl-2-carboxaldehyde as a solid (mp 97°-98°C.)

In a manner similar to Example 10, the reaction of5-(4-methylthiophenyl)thienyl-2-crboxaldehyde (3.0 g, 0.013 mole),hexamethylphosphorus triamide (33.4 g, 0.020 mole), andbromotrichloromethane (2.6 g, 0.013 mole) in methylene chloride (120 mL)produced 1.3 g of2-(2,2-dichloroethenyl)-5-(4-methylthiophenyl)thiophene as a solid (mp136°-139° C. )

Analysis: Calc'd for C₁₃ H₁₀ Cl₂ S₂ : C 51.83; H 3.35; Found: C 51.27; H3.31.

EXAMPLE 42 2-(2,2-Dichloroethenyl)-5-(4-methylsulfonylphenyl)thiophene

To a stirred solution of2-(2,2-dichloroethenyl)-5-(4-methylthiophenyl)thiophene (1.2 g, 0.0040mole) in methanol (50 mL) was added a solution of potassiumperoxymonosulfate (1.2 g, 0.0020 mole) in water (50 mL). After stirringfor one hour at room temperature, an additional 0.3 g of potassiumperoxymonosulfate was added, and a second addition of 0.3 g was madeafter an additional hour. After a total of about four hours of stirringat room temperature the mixture was extracted, first with diethyl ether,followed by methylene chloride. The extracts were combined and driedover anhydrous magnesium sulfate. The dried extract was filtered, andthe filtrate was evaporated under reduced pressure leaving a solidresidue. This residue was dissolved in isopropyl alcohol (15 mL), and asolution of potassium peroxymonosulfate (0.5 g) dissolved in about 5 mLof water was added. The resultant mixture was heated on a steam bath forapproximately one hour. The mixture was diluted with 400 mL of water andcooled to 0° C. for one hour. A solid formed and was collected byfiltration. The filter cake was dissolved in methylene chloride, and thesolution was dried over anhydrous magnesium sulfate. The dried solutionwas filtered, and the filtrate was evaporated under reduced pressure,leaving a solid residue. This residue was purified by columnchromatography on silica gel, eluting first with petroleum ether,followed by ethyl acetate, to yield 0.8 g of2-(2,2-dichloroethenyl)-5-(4-methylsulfinylphenyl)thiophene as a solid(mp 124°-126° C.) .

A mixture of 2-(2,2-dichloroethenyl)-5-(4-methylsulfinylphenyl)thiophene(0.8 g, 0.0025 mole) and m-chloroperbenzoic acid (2.0 g, 0.005 mole) inmethylene chloride (50 mL) was stirred at room temperature for two days.The mixture was poured into a 0.5N aqueous sodium thiosulfate solution.The resultant mixture was extracted with diethyl ether. The extract waswashed first with an aqueous 10% sodium hydroxide solution, followed byan aqueous 10% hydrochloric acid solution. The washed extract was driedover anhydrous magnesium sulfate and filtered. The filtrate wasevaporated under reduced pressure, leaving a solid residue. This residuewas purified by column chromatography on alumina, eluting withn-hexane:ethyl acetate (50:50), yielding 0.4 g of2-(2,2-dichloroethenyl)-5-(4-methylsulfonylphenyl)thiophene as a solid(mp 143°-145° C.).

Analysis: Calc'd for C₁₃ H₁₀ Cl₂ O₂ S₂ : C 46.85; H 3.02; Found: C47.88; H 3.05.

EXAMPLE 47 2-(2,2-Dichloro-1-fluoroethenyl)-5-phenylthiophene

Under a dry nitrogen atmosphere, a stirred mixture of 2-phenylthiophene(1.0 g, 0.006 mole) and diethyl ether (0.6 mL) was cooled to 0° C. Tothis cold mixture was added n-butyllithium (3.0 mL of a 2.1M solution inhexanes). After complete addition, the mixture was allowed to warm toroom temperature and was stirred for 45 minutes. This mixture was addedto a cold (-30°C.), stirred solution of 1,1-dichloro-2,2-difluoroethene(1.2 g, 0.009 mole) in diethyl ether (0.6 mL), also under a dry nitrogenatmosphere. After complete addition, the reaction mixture was heated atreflux for four hours. The reaction mixture was allowed to cool to roomtemperature and was stirred for approximately 18 hours. The mixture wasfiltered, and the filtrate was evaporated under reduced pressure,leaving an only residue.

This residue was subjected to distillation under reduced pressure (80°C. at 0.1 mmHg), leaving a brown oil. This oil was dissolved in warmpetroleum ether and, upon cooling, formed crystals. Collection of thecrystals by filtration yielded 0.6 g of2-(2,2-dichloro-1-fluoroethenyl)-5-phenylthiophene (mp 67°-68.5° C.).

Analysis: Calc'd for C₁₂ H₃ Cl₂ FS: C 52.76; H 2.58; Found: C 52.69; H2.60.

The following additional compounds were prepared by similar techniques,their identity being confirmed by elemental analysis and spectra.

    ______________________________________                                                                      Melting Point                                   Example                                                                              Name                   (°C.)                                    ______________________________________                                        1      2-(2,2-Dichloroethenyl)-5-phenyl-                                                                    92-94                                                  thiophene                                                              3      2-(2,2-Dibromoethenyl)-5-phenyl-                                                                     105-106                                                thiophene                                                              4      2-(2,2-Dichloroethenyl)-4-methyl-                                             5-phenylthiophene                                                      5      2-(2,2-Dichloroethenyl)-4-methyl-                                             5-(3-methylphenyl)thiophene                                            7      2-(2,2-Dibromoethenyl)-4-methyl-5-                                            (3-methylphenyl)thiophene                                              8      2-(2,2-Dichloroethenyl)-4,5-diphenyl-                                         thiophene                                                              9      2-(2,2-Dibromoethenyl)-4,5-diphenyl-                                          thiophene                                                              11     2-(2,2-Dibromoethenyl)-3,5-diphenyl-                                                                 125-130                                                thiophene                                                              12     2-(2,2-Dichloroethenyl)-3,4-dimethyl-                                         5-thiophene                                                            13     2-(2,2-Dibromoethenyl)-3,4-dimethyl-                                          5-phenylthiophene                                                      14     2-(2,2-Dichloroethenyl)-5-(2-methyl-                                                                 55-58                                                  phenyl)thiophene                                                       15     2-(2,2-Dibromoethenyl)-5-(2-methyl-                                                                  61-62                                                  phenyl)thiophene                                                       16     2-(2,2-Dibromoethenyl)-5-(2-methoxy-                                                                 81-82                                                  phenyl)thiophene                                                       17     2-(2,2-Dichloroethenyl)-5-(3-methyl-                                                                 58-59                                                  phenyl)thiophene                                                       18     2-(2,2-Dibromoethenyl)-5-(3-methyl-                                           phenyl)thiophene                                                       19     2-(2,2-Dichloroethenyl)-5-[3-(1-                                              methylethyl)phenyl]thiophene                                           20     2-(2,2-Dibromoethenyl)-5-[3-(1-methyl-                                        ethyl)phenyl]thiophene                                                 21     2-(2,2-Dichloroethenyl)-5-(3-methoxy-                                                                62-64                                                  phenyl)thiophene                                                       22     2-(2,2-Dibromoethenyl)-5-(3-methoxy-                                                                 63.5-65                                                phenyl)thiophene                                                       23     2-(2,2-Dibromoethenyl)-5-(4-fluoro-                                                                  95-98                                                  phenyl)thiophene                                                       24     2-(2,2-Dichloroethenyl)-5-(4-methyl-                                          phenyl)thiophene                                                       25     2-(2,2-Dibromoethenyl)-5-(4-methyl-                                                                  115-116                                                phenyl)thiophene                                                       26     2-(2,2-Dibromoethenyl)-5-[4-(1,1-                                             dimethylethyl)phenyl]thiophene                                         28     2-(2,2-Dichloroethenyl)-5-(4-methoxy-                                                                115-117                                                phenyl)thiophene                                                       29     2-(2,2-Dibromoethenyl)-5-(4-methoxy-                                                                 126-127                                                phenyl)thiophene                                                       30     2-(2,2-Dichloroethenyl)-5-(4-pentoxy-                                                                 98-100                                                phenyl)thiophene                                                       31     2-(2,2-Dibromoethenyl)-5-(4-pentoxy-                                                                   94-95.5                                              phenyl)thiophene                                                       32     2-(2,2-Dichloroethenyl)-5-(4-methoxy-                                                                79-80                                                  methoxyphenyl)thiophene                                                33     2-(2,2-Dibromoethenyl)-5-(4-methoxy-                                                                 72-75                                                  methoxyphenyl)thiophene                                                35     2-(2,2-Dibromoethenyl)-5-(4-benzoyl-                                                                 150-153                                                oxyphenyl)thiophene                                                    36     2-(2,2-Dibromoethyl)-5-(4-methoxycar-                                                                131-133                                                bonyloxyphenyl)thiophene                                               37     2-(2,2-Dibromoethenyl)-5-(4-methyl-                                           sulfonyloxyphenyl)thiophene                                            38     2-(2,2-Dibromoethenyl)-5-[4-(4-methyl-                                        phenyl)sulfonyloxyphenyl)thiophene                                     39     4-[2-(2,2-Dibromoethenyl)-5-thienyl]-                                         phenyl diethyl phosphate                                               40     2-(2,2-Dichloroethenyl)-5-(4-methyl-                                                                 116-118                                                thiophenyl)thiophene                                                   43     2-(2,2-Dichloroethenyl)-5-(naphth-1-                                          yl)thiophene                                                           44     2-(2,2-Dibromoethenyl)-5-(naphth-1-                                           yl)thiophene                                                           45     2-(2,2-Dichloroethenyl)-5-(naphth-2-                                                                 115-118                                                yl)thiophene                                                           46     2-(2,2-Dibromoethenyl)-5-(naphth-2-                                                                  107-109                                                yl)thiophene                                                           ______________________________________                                    

In the normal use of the insecticidal and acaricidal thienyl compoundsof the present invention, the thienyl compounds usually will not beemployed free from admixture or dilution, but ordinarily will be used ina suitable formulated composition compatible with the method ofapplication and comprising an acaricidally effective amount of thienylcompound. The thienyl compounds of this invention, like most pesticidalagents, may be blended with the agriculturally acceptable surface-activeagents and carriers normally employed for facilitating the dispersion ofactive ingredients, recognizing the accepted fact that the formulationand mode of application of an acaricide may affect the activity of thematerial. The present thienyl compounds may be applied, for example, assprays, dusts, or granules to the area where pest control is desired,the type of application varying of course with the pest and theenvironment. Thus, the thienyl compounds of this invention may beformulated as granules of large particle size, as powdery dusts, aswettable powders, as emulsifiable concentrates, as solutions, and thelike.

Granules may comprise porous or nonporous particles, such as attapulgiteclay or sand, for example, which serve as carriers for the thienylcompounds. The granule particles are relatively large, a diameter ofabout 400-2500 microns typically. The particles are either impregnatedwith the thienyl compound from solution or coated with the thienylcompound, adhesive sometimes being employed. Granules generally contain0.05-10%, preferably 0.5-5%, active ingredient as the acaricidallyeffective amount.

Dusts are admixtures of the thienyl compounds with finely divided solidssuch as talc, attapulgite clay, kieselguhr, pyrophyllite, chalk,diatomaceous earths, calcium phosphates, calcium and magnesiumcarbonates, sulfur, flours, and other organic and inorganic solids whichact as carriers for the acaricide. These finely divided solids have anaverage particle size of less than about 500 microns. A typical dustformulation useful for controlling acarids contains 1 part of thienylcompound, such as 2-(2,2-dibromoethenyl)-4-methyl-5-phenylthiophene, and99 parts of talc.

The thienyl compounds of the present invention may be made into liquidconcentrates by dissolution or emulsification in suitable liquids andinto solid concentrates by admixture with talc, clays, and other knownsolid carriers used in the pesticide art. The concentrates arecompositions containing, as an acaricidally effective amount, about5-50% thienyl compound and 95-50% inert material, which includessurface-active dispersing, emulsifying, and wetting agents, but evenhigher concentrations of active ingredient may be employedexperimentally. The concentrates are diluted with water or other liquidsfor practical application as sprays, or with additional solid carrierfor use as dusts.

A typical 50% wettable powder formulation would consist of 50.0% (wt/wt)of 2-(2,2-dichloroethenyl)-3,5-diphenylthiophene, 22.0% attapulgitedilute, 22.0% kaolin diluent, and 6.0% sodium salts of sulfonated Kraftlignin emulsifier.

Typical carriers for solid concentrates (also called wettable powders)include fuller's earth, clays, silicas, and other highly absorbent,readily wetted inorganic diluents. A solid concentrate formulationuseful for controlling acarids contains 1.5 parts each of sodiumlignosulfonate and sodium lauryl-sulfate as wetting agents, 25 parts of2-(2,2-dibromoethenyl)-4-methyl-5-phenylthiophene, and 72 parts ofattapulgite clay.

Manufacturing concentrates are useful for shipping low melting productsof this invention. Such concentrates are prepared by melting the lowmelting solid products together with one percent or more of a solvent toproduce a concentrate which does not solidify on cooling to the freezingpoint of the pure product or below.

Useful liquid concentrates include the emulsifiable concentrates, whichare homogeneous liquid or paste compositions readily dispersed in wateror other liquid carriers. They may consist entirely of the thienylcompound with a liquid or solid emulsifying agent, or they may alsocontain a liquid carrier such as xylene, heavy aromatic naphthas,isophorone and other relatively nonvolatile organic solvents. Forapplication, these concentrates are dispersed in water or ther liquidcarriers and normally applied as sprays to areas to be treated.

A typical 50 gram per liter emulsifiable concentrate formulation wouldconsist of 5.90% (wt/wt) of2-(2,2-dibromoethenyl)-4-methyl-5-phenylthiophene; as emulsifiers; 1.80%of a blend of the calcium salt of dodecylbenzene sulfonate and anonionic 6-molar ethylene oxide condensation product of nonylphenol,2.70% of a blend of the calcium salt of dodecylbenzene sulfonate and anonionic 30-molar ethylene oxide condensation product of nonylphenol,1.505 of a nonionic paste of polyalkylene glycol ether; and 88.10%refined xylene solvent.

Typical surface-active wetting, dispersing, and emulsifying agents usedin pesticidal formulations include, for example, the alkyl and alkylarylsulfonates and sulfates and their sodium salts; alkylamide sulfonates,including fatty methyl taurides; alkylaryl polyester alcohols, sulfatedhigher alcohols, polyvinyl alcohols; polyethylene oxides; sulfonatedanimal and vegetable oils; sulfonated petroleum oils; fatty acid estersof polyhydric alcohols and the ethylene oxide addition products of suchesters; and the addition products of long-chain mercaptans and ethyleneoxide. Many other types of useful surface-active agents are available incommerce. The surface-active agent, when used, normally comprises about1-15% by weight of the acaricidal composition.

Other useful formulations include simple solutions of the activeingredient in a solvent in which it is completely soluble at the desiredconcentration, such as acetone or other organic solvents.

An acaricidally effective amount of thienyl compound in an acaricidalcomposition diluted for application is normally in the range of about0.001% to about 8% by weight. Many variations of spraying and dustingcompositions known in the art may be used by substituting the thienylcompounds of this invention into compositions known or apparent in theart.

The acaricidal compositions of this invention may be formulated withother active ingredients, including other acaricides, nematicides,insecticides, fungicides, plant growth regulators, fertilizers, etc. Inusing the compositions to control acarids, it is only necessary that anacaricidally effective amount of thienyl compound be applied to thelocus where control is desired. Such locus may, e.g., be the acaridsthemselves, plants upon which the acarids feed, or the acarid habitat.When the locus is soil, e.g., soil in which agricultural crops are orwill be planted, the active compound may be applied to and optionallyincorporated into the soil. For most applications, an acaricidallyeffective amount will be about 50 to 750 g per hectare, preferably 150 gto 500 g per hectare.

The acaricidal activity of the thienyl compounds whose preparation isdescribed above was evaluated as follows:

The thienyl compounds were tested for acaricidal activity under normalambient light as well as near ultraviolet light (wavelength (320-400nanometer) at an intensity of 1600-2400 microwatts/cm² using testprocedures adapted to the organisms in the test. Regardless of theorganism, foliage of whole plants or foliage removed from whole plantswas sprayed to runoff with a 105 acetone-0.25%octylphenoxypolyethoxyethanol-water solution containing up to 250 ppm ofthe test compound.

Leaves infested with adult twospotted spider mites (Tetranychus urticae)were removed from culture plants and cut into segments containing 50-75female mites. Each segment was placed on the supper leaf surface of awhoe pinto bean (Phaseolus vulgaris) plant. After the mites had migratedto the under surfaces of the leaves, the leaf segments used to infestwere removed and each plant sprayed with test chemical as describedabove. After the plants had dried, the entire plant and pot were placedin metal trays in a hood. A supply of water in the tray kept the plantsturgid. Tests were conducted against both susceptible and phosphateresistant strains.

The test results were collected and recorded at the end of a 24 hour or48 hour exposure period. The data obtained under ultraviolet irradiationappear in Table 1. In contrast to those data, in the absence of theultraviolet light, and at a rate of 1000 rpm, the compounds gave zerokill in each case.

                  TABLE 1                                                         ______________________________________                                        ACARICIDAL EFFICACY                                                                          Exposure                                                       Cmpd. Rate     Time     % Kill.sup.1                                          of Ex.                                                                              (ppm)    (Hr)     TSM-PR TSM-R  TSM-S                                   ______________________________________                                        1     100      48                      100                                    2     100      48                      100                                    3     100      48       86     80      96                                     4     100      48              18      100                                    5     50       24                      57                                     6     100      48              100     100                                    7     50       24                      100                                    8     50       48                      3                                      9     50       48                      9                                      10    100      48                      100                                          32                       67                                             11    100      48              100     100                                    12    100      48                      100                                    13    100      48              52      100                                    14    100      48                      85                                     15    100      48                      13                                     16    250      48                      100                                    17    100      48              100     95                                     18    100      48              100     100                                    19    50       24                      41                                     20    50       24                      7                                      21    100      48                      97                                     22    100      48                      100                                    23    100      48              92                                                   20       48                      91                                     24    100      48                      70                                     25    250      48                      91                                     26    50       24                      55                                     27    50       48                      23                                     28    100      48                      98                                     29    100      48                      96                                     30    50       24                      100                                    31    50       24                      98                                     33    50       48              55      60                                     34    50       48                      74                                     35    50       48                      11                                     36    50       24                      4                                      37    50       48                      80                                     38    50       48                      76                                     39    100      24              36                                                   50       48                      47                                     40    50       24                      65                                     41    50       24                      70                                     42    50       24                      54                                     43    50       24              100     100                                    44    50       24                      97                                     45    50       24              73      100                                    46    50       24                      72                                     47    100      48                      100                                    ______________________________________                                         .sup.1 Acarid species                                                         TSM = twospotted spider mite (Tetranychus urticae) PR = Strain is             resistant to tricyclohexyltin hydroxide R = Strain is resistant to            phosphate insecticides S = Strain is not resistant to any types of            insecticides                                                             

What is claimed is:
 1. An acaricidal compound of the formula ##STR3## inwhich: R_(A) is hydrogen or a substituent at position 3' or 4' selectedfrom lower alkoxy, fluoro, methoxymethoxy, 3'-methyl, 4'-methyl if X isbromo, methylcarbonyloxy, methylphenylsulfonyloxy, methylsulfonyloxy,methylsulfonyl, methylthio, or O,O-diethyl phosphonyloxy,R_(B) ishydrogen or R_(A) and R_(B) together are --C₄ H₄ -- bridging positions2'-3+ or 3'-4'; R₃ is hydrogen, methyl, or phenyl; R₄ is hydrogen ormethyl; and X is bromo or chloro.
 2. An acaricidal compound of claim 1in which:(a) R_(A) is hydrogen or a substituent at position 3' or 4'selected from lower alkoxy, methoxymethoxy, 3'-methyl, methylthio, ormethylsulfonyl;R_(B) is hydrogen or R_(A) and R_(B) together are --C₄ H₄-- bridging positions 2'-3' or 3'-4'; R₃ is hydrogen, methyl, or phenyl;R₄ is hydrogen or methyl; and X is chloro; or (b) R_(A) is hydrogen or asubstituent at position 3' or 4' selected from lower alkoxy, fluoro,methoxymethoxy, methyl, methylcarbonyloxy, methylphenylsulfonyloxy,methylsulfonyloxy, methylthio, or O,O-diethyl phosphonyloxy;R_(B), R₃,and R₄ are as defined above; and X is bromo. 3.2-(2,2-Dibromoethenyl)-4-methyl-5-phenylthiophene, a compound ofclaim
 1. 4. 2-(2,2-Dibromoethenyl)-3,4-dimethyl-5-phenylthiophene, acompound of claim
 1. 5.2-(2,2-Dichloroethenyl)-5-(naphth-1-yl)thiophene, a compound of claim 1.6. 2-(2,2-Dibromoethenyl)-5-phenylthiophene, a compound of claim
 1. 7.2-(2,2-Dibromoethenyl)-5-(4-fluorophenyl)thiophene, a compound ofclaim
 1. 8. 2-(2,2-Dibromoethenyl)-5-(4-acetyloxyphenyl)thiophene, acompound of claim
 1. 9.2-(2,2-Dibromoethenyl)-5-(4-methylsulfonyloxyphenyl)thiophene, acompound of claim
 1. 10. 2-(2,2-Dichloroethenyl)-5-phenylthiophene, acompound of claim
 1. 11.2-(2,2-Dichloroethenyl)-4-methyl-5-phenylthiophene, a compound ofclaim
 1. 12. 2-(2,2-Dibromoethenyl)-5-(3-methylphenyl)thiophene, acompound of claim
 1. 13. An acaricidal composition comprising anacaricidally effective amount of at least one compound of claim 1 inadmixture with an agriculturally acceptable carrier.
 14. A method forcontrolling acarids which comprises applying to the locus where controlis desired an acaricidally effective amount of at least one compound ofclaim 1.